Terry T.-K. Huang

Eating patterns and dietary composition in relation to BMI in younger and older adults

Objective:To compare relative associations of eating patterns and dietary composition with body mass index (BMI) in younger (aged 20–59 years, n=1792) and older (aged 60–90 years, n=893) participants in the Continuing Survey of Food Intakes by Individuals, collected 1994–1996.Methods:Data from two 24-h dietary recalls from individuals reporting physiologically plausible energy intake (within ±22% of predicted energy requirements, based on previously published methods) were used.Results:Mean reported energy intake was 96 and 95% of predicted energy requirements in younger and older subjects, respectively. Older subjects were less likely than younger subjects to skip a meal, but snacking was common in both age groups. Fiber density was significantly higher in the older group. A higher BMI in both age groups was associated with a higher total daily energy intake, and higher energy intakes at all eating occasions. In both age groups, eating frequency was positively associated with energy intake, and eating more than three times a day was associated with being overweight or obese. In the younger group but not the older group, a lower fiber density coupled with higher percentage of energy from fat was independently associated with having a higher BMI.Conclusions:While no one eating occasion contributes more than any other to excess adiposity, eating more often than three times a day may play a role in overweight and obesity in both younger and older persons. A reduced satiety response to dietary fiber in addition to lower energy expenditure may potentially further contribute to weight gain in older persons.

Eating Frequency and Energy Regulation in Free-Living Adults Consuming Self-Selected Diets

The relative importance of eating frequency to weight control is poorly understood. This review examines the evidence to date on the role of eating frequency in weight control in free-living adults. The majority of cross-sectional studies in free-living adults show an inverse relationship between eating frequency and adiposity; however, this is likely an artifact produced by the underreporting of eating frequency concurrent with underreporting of energy intake. When implausible energy intake reporting (which is mostly underreporting) is taken into account, the association between eating frequency and adiposity becomes positive. In studies in which eating frequency is prescribed and food intake is mostly self-selected, there is either no effect or a minor positive effect of eating frequency on energy intake. Most of those studies have been short-term and lack the necessary dietary biomarkers to validate reported energy intakes and eating frequencies. In conclusion, there is some suggestion from cross-sectional studies in which energy intake underreporting is taken into account and from experimental studies to date that greater eating frequency may promote positive energy balance. However, experimental studies of longer-term duration that include objective dietary biomarkers are necessary before firm conclusions about the relative importance of eating frequency in weight control can be made.

Birth weight, puberty, and systolic blood pressure in children and adolescents: a longitudinal analysis

We examined the association between birth weight and systolic blood pressure (SBP) from pre-puberty to late puberty in a cohort of American children. Ninety-eight children aged 4–12 years at baseline were followed annually for 2–6 years with at least two Tanner stages. Annual measures included SBP, age, gender, race, birth weight, Tanner stage, and body composition using dual-energy X-ray absorptiometry and computed tomography. Birth weight was inversely correlated with SBP in pre-pubertal children (r=−0.23, P<0.05), especially in white children. SBP persisted at a higher level from pre-puberty through late puberty among children with low birth weight (<2500 g). However, SBP significantly increased from pre-puberty to early or late puberty among children with high birth weight (⩾4000 g). After adjusting for visceral fat, one unit change of birth weight category was associated with a 2.6 mm Hg reduction in SBP (P<0.05), but this association was attenuated as puberty progressed. The changes in SBP across puberty followed different trajectories in children with low vs high birth weight. Attenuation in the association between birth weight and SBP from pre-puberty to late puberty may be influenced by sexual maturation.

#78 Birth weight modifies the relationships between systolic bloodpressure, pubertal development, and body mass in adolescents

PURPOSE: Studies have shown that systolic blood pressure (SBP) is positively associated with body size and sexual maturation, but inversely associated with birth weight during childhood. The aim of the this longitudinal study was to examine the moderating effects of birth weight on the associations of SBP with pubertal development and body mass in Caucasian and African American children. METHODS: One hundred and thirty nine children aged 4 to 12 years at the start of the study were followed up annually for 3 to 5 years with an average of 4 repeated measures for each subject (n = 560 observations) in Birmingham, Alabama. Characteristics measured annually included blood pressure, Tanner stage, and body composition from dual energy x-ray absorptiometry. RESULTS: SBP was inversely correlated with birth weight (r = −0.10, p = 0.02), especially in Caucasian children (r = −0.16, p = 0.002). Larger BMI was significantly associated with higher SBP (p < 0.001). Lower birth weight was significantly associated with a faster increase of SBP with respect to the increase of BMI (β = −0.4, p < 0.05). In contrast, lower birth weight was significantly associated the slower increase of SBP with pubertal development (β = 1.3, p < 0.10). CONCLUSION: The findings from this longitudinal study suggest that birth weight may modify the effects of body size and pubertal development on the increase of SBP during adolescence.